Given a DNA strand, return its RNA complement (per RNA transcription).
Both DNA and RNA strands are a sequence of nucleotides.
The four nucleotides found in DNA are adenine (A), cytosine (C), guanine (G) and thymine (T).
The four nucleotides found in RNA are adenine (A), cytosine (C), guanine (G) and uracil (U).
Given a DNA strand, its transcribed RNA strand is formed by replacing each nucleotide with its complement:
For installation and learning resources, refer to the exercism help page.
For running the tests provided, you will need the Minitest gem. Open a terminal window and run the following command to install minitest:
gem install minitest
If you would like color output, you can
require 'minitest/pride' in
the test file, or note the alternative instruction, below, for running
the test file.
Run the tests from the exercise directory using the following command:
To include color from the command line:
ruby -r minitest/pride rna_transcription_test.rb
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
require 'minitest/autorun' require_relative 'rna_transcription' # Common test data version: 1.0.1 cb1fd3a class RnaTranscriptionTest < Minitest::Test def test_rna_complement_of_cytosine_is_guanine # skip assert_equal 'G', Complement.of_dna('C') end def test_rna_complement_of_guanine_is_cytosine skip assert_equal 'C', Complement.of_dna('G') end def test_rna_complement_of_thymine_is_adenine skip assert_equal 'A', Complement.of_dna('T') end def test_rna_complement_of_adenine_is_uracil skip assert_equal 'U', Complement.of_dna('A') end def test_rna_complement skip assert_equal 'UGCACCAGAAUU', Complement.of_dna('ACGTGGTCTTAA') end def test_correctly_handles_invalid_input_rna_instead_of_dna skip assert_equal '', Complement.of_dna('U') end def test_correctly_handles_completely_invalid_dna_input skip assert_equal '', Complement.of_dna('XXX') end def test_correctly_handles_partially_invalid_dna_input skip assert_equal '', Complement.of_dna('ACGTXXXCTTAA') end # Problems in exercism evolve over time, as we find better ways to ask # questions. # The version number refers to the version of the problem you solved, # not your solution. # # Define a constant named VERSION inside of the top level BookKeeping # module, which may be placed near the end of your file. # # In your file, it will look like this: # # module BookKeeping # VERSION = 1 # Where the version number matches the one in the test. # end # # If you are curious, read more about constants on RubyDoc: # http://ruby-doc.org/docs/ruby-doc-bundle/UsersGuide/rg/constants.html def test_bookkeeping skip assert_equal 4, BookKeeping::VERSION end end
class Complement DNA_KEYS = 'GCTA'.freeze RNA_KEYS = 'CGAU'.freeze def self.of_dna(dna) return '' unless valid_dna?(dna) dna.tr(DNA_KEYS, RNA_KEYS) end def self.valid_dna?(dna) (dna.chars - DNA_KEYS.chars).none? end end module BookKeeping VERSION = 4 end
A huge amount can be learned from reading other people’s code. This is why we wanted to give exercism users the option of making their solutions public.
Here are some questions to help you reflect on this solution and learn the most from it.